HTML5 pattern for phone number formatting

Question

<input type="text" pattern=" ">

How to make pattern to work with below formats?

note:

• zero always the first number
• allow only number and space in between
• accept only 11 or 12 characters (include spaces)

sample:

1. 0xx xxx xxx
2. 0xx xxx xxxx

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Many thanks :)

Answer 1

pattern="0[0-9]{2} [0-9]{3} [0-9]{3,4}"